Heat treatment



INVENTOR 4 SHEETS-SHEET 3.

Fuv.

Patented Dec. 14, 1920.

R. E. TALLEY. HEAT TREATMENT.

APPLICATION man ocr. 4,1919.

cc i/f/f/ UNITED STATES PATENT OFFICE.

RANDAL E. TALLEY, OF IRWIN, PENNSYLVANIA, ASSIGNOR TO THE GEORGE J. HAGAN COMPANY, 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

HEAT TREATMENT.

Application led October 4, 1919.

To all whom it may concern.'

Be it known that I, RANDAL E. TALLEY, residing at Irwin, in the county of lVestmoreland and State of Pennsylvania, a citi- Zen of the United States, have invented or discovered certain new and useful Improvements in Heat Treatment, of which improvements the following is a specification.

The invention described herein relates to vthe annealing or heat treatment of metal articles having small transverse sections, such as wire rods, strips or sheets, and has for its object the subjection of such articles while moving continuously through a heating chamber to heat radiated from the heating elements, extending parallel with the direction of movement ofthe article and also to -heat refiected from the walls of such chamber, and at the same time protecting the article from oxidation and the action of injurious gases. The invention is hereinafter more fully described and claimed.

In the accompanying drawings forming a part of this specification, Figure l is a view partly in elevation and partly in section of a form of furnace embodying improvements described herein; Fig. 2 is a sectional plan view on a plane indicated by the line II-II, Fig. 1; Fig. 3 is a vertical section on a plane indicated` by the line III-III, Fig. l; Fig. 4 shows a desirable wiring arrangement for three phase supply; Fig. 5 is a sectional View illustrating a modification of the manner of supporting the heating element; Fig. 5a is a sectional elevation of the construction shown in Fig. 5, the plane of section being at right angles to that of Fig. 5; Fig. 6 is a perspective section showing a modification of the means of supporting the heating element; Fig. 7 is a partial section showing the assembly of this method of support; Figs. 8 and 9 are perspective views illustrating further modifications, and Fig. l0 is a View partly in perspective and partly in section showing the manner of introduc ing heat generated by combustion of fuel into the tunnels.

In the practice ofthe invention the furnace is provided with a plurality of tunnels or passages l. through which' the articles to be treated are continuously passed. These Specification of Letters Patent.

' Patented Dec. 14, 1920.

Serial No. 328,359.

passages or tunnels are formed in the hearth of the furnace by a suitable arrangement of fire brick except t the end portions which are preferably formed of tubes 2 of fire clay, metal or other suitable material. Provision is made for heating the tunnels by the arrangement of heating elements partially or wholly within the tunnels, said elements being of such a character and so heated that no injurious gases are formed 1n or can enter the tunnels. In the construction shown in Figs. l to 4 inclusive, provision is made for heating the tunnels electrically and resistance elements 3 consisting of ribbons or strips preferably formed of nickel chromium alloy are supported in the upper portions of the tunnels out of the path of movements of the articles through the tunnels. These ribbons are so supported that the articles passing through the tunnels are subjected to heat from a large proportion of the surfaces of the ribbons. In the construction shown in Figs. 1 to 3, the ribbons are supported by refractory blocks 4 of electrically non-conducting material. These blocks have their ends supported by the side walls of the tunnels and are spaced a suitable distance apart dependent on the rigidity of the ribbon when heated. In order that the articles may be directly subjected to the radial heat from large proportions of the surfaces of the ribbons, the portions of the supporting blocks intermediate their ends are reduced in transverse dimensions, as shown in Figs. 1, 2 and 3.

The terminals 5 of the ribbons extend out through tubes 6 formed of nonconducting material and their outei` ends are suitably connected to supply conductors 7 and to each other. Vhile the connections ,are shown for three-phase alternating current it is obvious that any commercial electrical supply either alternating or direct current can be employed with equally good results.

The alternative method of supporting the resistors shown in Fig. 5 is especially applicable where the tunnels must be of considerable width to accommodate strips or sheets of metal. The roof of the furnace may be of any suitable fiat suspended arch construction, for example, the Dietrich arch. To provide recesses to accommodate the heating elements, certain4 of the tiles or bricks, as 8, project down into the tunnel. The sides of the projecting portions of the tiles are so constructed as to engage and hold as against downward movement blocks 9 adapted to serve as electrically insulating supports for the resistors. `While engagement between the tiles and the bearing blocks may be e'ected in many ways, it is preferred to. so incline the adjoining faces ot adjacent tiles as to form longitudinal recesses having downwardly converging walls forming a dovetail slot. rThe bearing blocks have their opposite sides oppositely inclined so as to wedge in between the faces of adjoining tiles. rlFhese bearing blocks are slid into the ends of the recesses or grooves formed by the projecting portions of the tiles and `can be pushed along the same to proper position. i

ln the construction shown in Figs. 6 and 7, the walls forming the sides of the tunnels are provided with laterally projecting lugs l0 in which are formed slots 1l adapted to support the resistor ribbons on .edge or approximately parallel with the sides of the tunnels.

ln lieu of separating adjacent tunnels by continuous side walls, they may be separated by a multiplicity of piers or abutments l2, which are provided with slots 13 as shown in Fig. 8, or with openings la as shown in Fig. 9, adapted to support the ribbons on edge. lt is characteristic et the construction shown in Figs. i5 to 9 that each tunnel will receive the heat radiated from a plurality of resistors. .find further, by supporting the ribbons so that their faces are parallel with the sides the tunnels, the wire being treated will receive direct radiation :from the largest possible amount et resistor surfaces.

lieu of heating the tunnels electrically as hereinbefore desc Hbed, they may be heated by the cembusu en et' any suitable fuel, whether solid or uid, and transmitting the heat so gene ed to the tunnels by a heat conducting element. This method ci heating the tunnels can be carried out in many ways, such for e ample as that shown in Fig. l0. is therein shown, the 'furnace is provided with 'tunnels le; termed in the hearth of the ilu substantial manner shown in i f2 and 3, these tunnels is z chamber' l5 the shape which will depend en the chars 'fuel employed. rlhs heat gene combustion chamber nels by heat condut a melting point highs required and exten` r. of the d in the conducted the tunelements i6 having nasales? tion chamber into the tunnels. ln the construction shown the heat conducting elements are formed by metal strips embedded in the hearth and or' such a width that portions will project down into the tunnels while the opposite edge will extend in such manner into the combustion chamber that it may be highlyheated.

llt will be understood that under the term means for heating includes in the one form the electric generator and in the other form the combustion chamber in which the products of combustion are brought into contact with the metal strips.

l claim herein as my invention l. As a means for the continuous heat treatment of articles, having one of their cross sectional dimensions relatively small comprising a bed or mass of masonry provided with a plurality of tunnels or passages through which the articles to be treated may be fed continuously and heating elements arranged within the tunnels and adapted to be raised to a high temperature without the formation of injurious gases within the tunnels and means exterior of the tunnels for raising the temperature of the heating elements.

2. A means for the continuous heat treatment of articles having one of their cross sectional dimensions relatively small comprising a bed or mass of masonry provided with 'a plurality of tunnels or passages through which the articles to be treated may be continuously fed, heating elements e3;- tending along said tunnels substantially parallel with the axes of the tunnels and means exterior of the tunnels for raising the temperature of the heating` elements.

3. il means `for the continuous heat treatment of wires or sheets, comprising a bed or mass of masonry provided with a pluality or' tunnels or passages through which the articles to be treated may be continuously i'ed, a heating clement :tormed oi a material able of being raised to a high temperati e without the generation or' injurious gases, so supported in the tunnels that the wire or sheet will be acted on directly by heat radiated from the heating element and means exterior of the tunnels for raising the temperature of the heating elements.

il; means for the continuous heat treat l e or sheets comprising a tunnel through which. the articles may Vv.ed continuously, a metal strip arranged within the tunnel in suitable proximity to the path of movement of the wire er sheet through the tunnel. and means exterior of' the tunnel :fior raising the temperature et tal strip.

means Jor continuous heat treatment comprising a tunnel hrcurfh which the aA fed continuously, a metal strip arranged moving` the Wire or sheet along an electri- Within the tunnel in suitable proximity to cally heated strip and insuch relation therethe path of movement of `the Wire or sheet to that the Wire or sheet Will be subjected to 10 through the tunnel and means for raising heat radiated from the strip. 5 the temperature of the metal strip. ln testimony whereof I have hereunto set 6. The method herein described of heat my hand. treating wire or sheets which consists in RANDAL E. TALLEY. 

